Total and domestic consumption of salt and their determinants in three regions of Italy.

Total and domestic (discretionary) consumption of salt was assessed in a sample of 91 households, which were randomly selected in three areas of Italy characterized by different dietary habits. Total salt intake was estimated by the mean urinary sodium in four 24 h collections. Discretionary salt, added during the preparation of the meals or at the table, was assessed using a simplified protocol of the lithium marker technique. Total sodium excretion was 191 mmol/d, 160 mmol/d and 132 mmol/d in adult males, adult females and children respectively. Dietary sodium density was 15 mmol per MJ of energy in children and 19 mmol/MJ in adults. It was significantly lower in the area where the traditional consumption of unsalted bread persists. Discretionary sodium intake was 67 mmol/d in adult males and females and 43 mmol/d in children; equivalent respectively to 36 per cent, 39 per cent and 34 per cent of total sodium intake. No difference was found between urban and rural environments, whereas discretionary use of salt was higher in the lower social class. These findings have important nutrition policy implications for the lowering of salt intake in the general population.